Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /home/qcsvlel/www/core/modules/file/src/Validation/FileValidationEvent.php:12 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/file/src/Validation/FileValidationEvent.php on line 12